1. Field of the Invention
The present invention relates to an apparatus for positioning a sensor in an operative location relative to a related part, and more particularly to a marine propulsion device including an internal combustion engine incorporating a crankshaft mounted timing ring, and a sensor operable to provide crankshaft angular position information to time the ignition spark of the internal combustion engine.
2. Description of the Prior Art
The prior art includes sensor devices and arrangements for positioning such sensors devices which are individually operable to time the spark sequence of an internal combustion engine. Examples of such sensor devices and positioning arrangements are shown in U.S. Pat. No. 4,406,272 to Kiess et al; U.S. Pat. No. 4,373,486 to Nicholas et al U.S. Pat. No. 4,508,092 to Kiess et al; and U.S. Pat. No. 4,635,353 and U.S. Pat. No. 4,677,946 to Tamange.
Marine propulsion devices such as stern drive units have employed an electronic ignition system including a sensor consisting of a molded electrical connector and sensing element assembly bonded to a housing and including three parallel probes. A magnet is bonded into the central probe and the outer probes act as Hall effect devices. The sensor provides crankshaft angular position information to an electronic control module that controls the spark sequence of the internal combustion engine. A crankshaft mounted timing ring, which has a plurality of vane segments and which further has common rotation with the crankshaft, activates the sensor. The sensor is mounted on the internal combustion engine such that the vane segments pass through a pair of spaces defined between the probes. The movement of the vane segments through the spaces defined by the probes has the effect of shunting the magnet flux fields generated by the probes and thereby generates a predetermined series of pulses at the electronic control module that is indicative of the firing order of the internal combustion engine.